IBM Using Transport Layer Security (TLS) with the Sametime Media Manager 8.5.2 server and pre-8.5.2 Sametime clients in a clustered environment https://www.ibm.com/support/docview.wss?uid=swg21567676 Java cores show many instances of com.ibm.ws.sip.container.tu.TransactionUserWrapper listing it as a possible leak suspect. There are also entries in the logs showing a NullPointer Exception: SignalingEndO E SignalingEndOfTask java.lang.NullPointerException at com.ibm.ws.sip.container.proxy.StatefullProxy. handleStrayInvite2xx(StatefullProxy.java:1360) at com.ibm.ws.sip.container.tu.TransactionUserImpl. processProxyStrayInvite2xx(TransactionUserImpl.java:3422) at com.ibm.ws.sip.container.tu.TransactionUserImpl. processStrayInvite2xx(TransactionUserImpl.java:3320) at com.ibm.ws.sip.container.tu.TransactionUserImpl. processStrayResponse(TransactionUserImpl.java:3289) at com.ibm.ws.sip.container.tu.TransactionUserWrapper. processStrayResponse(TransactionUserWrapper.java:704) at com.ibm.ws.sip.container.router.tasks. StrayResponseRoutedTask.doTask (StrayResponseRoutedTask.java:97) at com.ibm.ws.sip.container.router.tasks.RoutedTask. run(RoutedTask.java:76) at com.ibm.ws.sip.container.was.SignalingEndOfTask. run(SignalingEndOfTask.java:67) at com.ibm.ws.util.ThreadPool$Worker. run(ThreadPool.java:1646)